1. Technical Field
The disclosure relates to a wireless detection apparatus and a wireless detection method.
2. Description of Related Art
In recent years, with the improvement of people's life, people have started paying attention to their health problems. Since the majority of people ignore alerting signals sent by their bodies, they often didn't realize their health problems before their health conditions or living environments become worse. Accordingly, in order to allow ordinary people to observe their physiological conditions on their own, various measurement instruments have been introduced. As such, ordinary people can use various measurement instruments to monitor physiological changes in their bodies, such that they can timely perceive their health problems and therefore have proper rest according to their physical fitness.
There are generally two types of designs of the conventional physiological signal detection circuit. One is the contact type physiological signal detector, and the other is the non-contact type physiological signal detector. Contact type physiological signal detectors generally perform the measurement by contacting human bodies. The contact type physiological signal detectors have simple circuit architecture. However, because of the necessity of contacting the human body, the detection circuit may make the user feel uncomfortable if the detector is used for a long time.
On the other hand, non-contact type physiological signal detectors are generally constructed on the basis of Doppler radar. In a conventional Doppler radar construction, a sinusoidal signal is generated and transmitted through a power splitter. One way of outputs of the power splitter is connected to an antenna so as to radiate the sinusoidal signal to the human thorax. The sinusoidal signal experiences a Doppler effect due to the up and down movement of the thoracic wall. After the reflected signal and the signal from another output of the power splitter are mixed through a mixer and undergo subsequent processing, physiological information for observation can be obtained. However, in this physiological signal detector, the phase difference between the reflected wave and the wave from the another output of the power splitter may cause a destructive interference and therefore lead to a detection zero-point at some particular positions where detection is made impossible, which limits the use of this non-contact type detector. In addition, this type of detector has complex circuit architecture, high power consumption and high cost. Furthermore, the detecting results may be inconsistent due to variation of the detecting distance.